Press Strokes, Parts and Rejects: A Counting Specification

Use the working record

Download the editable worksheet. Record the actual evidence and responsible reviewer against each relevant row. The empty results are inputs for your project, not completed tests. Add the equipment identity, operating period and reference method before assigning an outcome. Retain unsuccessful checks and the evidence from any repeat after correction.

Name the event at the sensor

Identify exactly what causes the acquired signal: a position transition, a controller event or another approved machine output. Record its polarity, duration and expected sequence. A sensor can change state twice during a stroke, and a sampled level can remain active across several reports. Neither should automatically become two produced units.

Ask the machine specialist to define the permissible connection and observation method. The counting integration should use the accepted monitoring interface. Document the source and how a complete event is recognised, including any filtering or debounce rule that affects closely spaced transitions.

Map tooling to physical output

For each tool or die, record the number of intended parts produced by a completed production stroke. Keep disabled cavities, progressive tooling and multiple operations explicit. A fixed multiplier entered during commissioning can become wrong when tooling or the production configuration changes.

Connect the tooling record to a work order or effective time. Preserve the previous value rather than editing historical reports with today's cavity count. Where the machine produces an intermediate item, name that output clearly and identify the later operation that establishes the final part count.

Separate setup and production strokes

Define how the line identifies setup, trial, production and maintenance activity. These classifications may come from a verified controller state or a controlled operator entry. Keep the supporting source and timestamp so a reviewer can understand why a counted stroke was included in a production total.

Trial material can move into accepted production only under the site's actual quality process. Avoid silently removing setup strokes from the raw counter. Retain the complete machine event history and apply the approved reporting classification as a separate interpretation, with revisions visible.

Build an explicit quantity reconciliation

Start with verified production strokes and the effective output relationship. Then reconcile physical units, rejected units and any relevant work in progress. A stroke-derived expectation and a counted container quantity can disagree because of handling, sampling or tooling configuration; the discrepancy is an investigation item.

Keep rejects in the unit used by the report. If scrap is recorded by mass while production is recorded by pieces, the conversion needs an accepted basis. Do not subtract a mass value from a piece total or assume every rejected stroke corresponds to the same number of rejected parts.

Test awkward sequences deliberately

Use an authorised test plan that includes a normal run, a short stop, an incomplete cycle and a mode change. Observe the actual physical output alongside the signal. Select a safe method with the responsible machine personnel; the monitoring test does not require bypassing existing machine protection.

Include the fastest relevant event sequence and a low-speed setup sequence. Confirm that the acquisition configuration captures valid events without counting contact bounce or repeated reports. Retain the raw evidence where available so a discrepancy can be traced to the event rule rather than explained only through a final total.

Make resets and replacement visible

Determine whether the source is an incrementing counter or individual events. For a counter, record its range, rollover behaviour, reset conditions and persistence through power interruption. Calculate interval production using the accepted counter logic, with resets flagged for reconciliation.

When a sensor or controller is replaced, close the old identity and open the new one with an effective timestamp. Keep closing and opening values and the witnessed check. Treating the replacement as a continuous counter can create a large negative quantity or an artificial production surge.

Assign late quality results to the right period

A quality team may reject parts after the machine shift has ended. Retain both the production period and the disposition time. The reporting rule should explain whether the earlier result becomes provisional, is revised or appears with a linked later adjustment.

Rework needs its own route. A second pass through the press can create additional strokes without creating additional unique saleable parts. Link the rework event to the original batch where the process permits it, and preserve the distinction between machine activity and net accepted output.

Accept the report with a witnessed reconciliation

Choose a bounded run with identified tooling, material and operating mode. Compare the raw event count, interpreted strokes, expected pieces, physical count and quality disposition. Record each difference and its explanation. Acceptance tolerances should follow the intended measurement and counting method rather than an arbitrary universal percentage.

Handover includes the event rule, tooling register, reset procedure and reporting examples. Assign production, quality and maintenance owners to their respective inputs. Repeat relevant checks after tooling changes or signal work so the report remains tied to the press's actual output relationship.

Connect the decision to the project

Use Stamping press monitoring, Oee monitoring production environments to place this task within the wider installation. Bring a recent operating record and identify the decision that the proposed measurement should support. A focused discussion should establish the first boundary, the responsible site participants and the evidence needed before expanding the scope.

Agree who maintains the point register and who can change interpretation rules. Preserve the previous version when a device, product, reporting period or responsibility changes. During handover, demonstrate an export that another authorised person can reconcile without relying on the dashboard operator to explain missing fields.

Discuss the scope with addanode using the actual site information, available interfaces and proposed acceptance record.

Sources and method

Vorne’s OEE calculation guidance explains the role of total and good counts. The press event and tooling rules in this worksheet must be verified against the installed machine.

Frequently asked questions